Why is Madame Schachter significant in the novel Night?

I would say that Madame Schachter is an important
character because she reflects the cruelty that the victims of the Holocaust displayed
toward one another.  In his speech, "The Perils of Indifference," Wiesel talks about how
the most repugnant aspect of the Holocaust was that it bred indifference and cruelty
between human beings.  The dehumanization that the Nazis displayed towards those who
were victims of the Holocaust was also present in how those very victims treated one
another.  Like Moshe the Beadle, Madame Schachter's presence in the narrative is a quick
one, but it is one that lingers.  When she starts screaming on the train, Wiesel
displays the callous and brutal attitudes of the other passengers towards her.  No one
takes care of her, or looks out for her.  Rather, the passengers are quite easily driven
to silence her physically and mentally.  Even her own son is silent in the measures
taken to get her to be quiet.  It is reflective of the sadness in the Holocaust that her
visions of fire and burning turn out to be true.  In Madame Schachter, the ultimate
lesson learned is that the silencing of any voice by any force is an awful condition. 
It is one that was replicated all too often during the Holocaust and one that was
silenced by other victims.  In this assessment, one recognizes the Holocaust as a human
tragedy, one where ethical treatment of one another is of vital importance to its
study.  It is here where Madame Schachter's character occupies the greatest of
importance.